Effect of surface roughness pattern on transient mixed elastohydrodynamic lubrication

Abstract

Besides the surface roughness of two contacting surfaces, the surface roughness pattern i.e. longitudinal, transverse and isotropic significantly influences the tribological performance of the mechanical element. Their impression is more pronounced under the mixed elasto-hydrodynamic lubrication condition. The cam and flat follower mechanism is a typical sample in which adverse tribological conditions, including direct boundary interactions occurs. In this paper, the effect of surface roughness pattern on the film thickness and friction coefficient in a cam follower mechanism is investigated. Asperity interaction and friction coefficient analysis is conducted based on a novel elasto-plastic model. The lubrication model is qualitatively compared with the experimental results obtained from the pin on disk experiments for various surface roughness orientations. The results of transient lubrication analysis for a cam and follower lubrication problem are presented. It is shown that the longitudinal surface roughness pattern has a more desirable tribological performance than transverse surface pattern.